Re: [CAD_CAM_EDM_DRO] DRO/linear encoder
Posted by
james owens
on 2000-04-27 14:29:26 UTC
Hi Rich,
I have no doubt that someone here will disagree with my thoughts on this. This is as it should be for with agreement there is no discussion.
I am also embarking on this route. My miller is an old war finish Bridgeport type of machine that is called a Beaver.
I have given this set-up some thought over the last few weeks. I am using the Camtronics 4 axis board with software from Tom Kulaga. I thought it false economy to just buy the 2 axis board when the 4 was only a few more penny's. As sure as eggs is eggs I'll want to go the whole lot as soon as the first axis works and I wonder how anything was ever machined pre DRO.
I bought 3 encoder strips 360 and 1 rotary encoder, the correct HEDS from USDigital. I looked around before parting with the cash and decided this was the cheapest route. There is much written on this list about glass and metal encoder strips with resolutions in the micron range and prices to match, but I am a machinist used to micrometers that read in thou and an old machine that has seen better days.
The HEDS are optical readers and you will not damage either them or the strip by just touching them together. If you look at the USDigital website they have drawings for the installation measurements.
The first decision is if the HED or the strip is going to be attached to the moving slide. I opted to move the HED alone the strip because it is easier to seal out the muck. Obtain a piece of aluminium angle of the required length that is straight, double sided tape and stick the encoder strip to it leaving the correct overhang for the HED. I screwed the angle to the machine and checked it with a dial gauge before sticking down the strip. Make up a block on which to mount the HED in the correct position, wire it up and check that the DRO works.
The next step is to seal out the grubby bits. I got a length of box section aluminium that the angle and the HED could fit inside leaving enough room for the wires. Then cut a slot along the length of the box to clear the angle and the run of the HED. I am using the same screws that mount the angle to mount the box. This means drilling corresponding holes in the front of the box so everything can be tightened up. These are then blocked up with little rubber bungs.
Feed the wires through and block up the ends and everything should be swarf and oil tight.
Terry.
Dear List,
Let me first say that I am in over my head and need advice. I am
trying to put together a DRO to measure travel of my Bridgeport knee.
The plan is to use a 2 axis DRO kit from Camtronics and a HEDS-9200
module with a 360 linear strip from US Digital. My questions concern
mounting of the linear strip. US Digital says this can be done using
double stick tape or drilling hole and using screws/aluminum mounts. Is
there a web site that might have a picture of a mounting? I know that
the protection of the encoder is also important. US Digital said that
linear strip runs inside module (makes sense) but doesn't touch it. If
it did touch would that destroy the strip or the module? Is it like
crashing a hard drive?
Any thoughts on this subject will be appreciated. I want to try this
installation rather than just buying a DRO.
Thanks in advance,
Richard Ronchi (Santa Clara, Ca)
[Non-text portions of this message have been removed]
I have no doubt that someone here will disagree with my thoughts on this. This is as it should be for with agreement there is no discussion.
I am also embarking on this route. My miller is an old war finish Bridgeport type of machine that is called a Beaver.
I have given this set-up some thought over the last few weeks. I am using the Camtronics 4 axis board with software from Tom Kulaga. I thought it false economy to just buy the 2 axis board when the 4 was only a few more penny's. As sure as eggs is eggs I'll want to go the whole lot as soon as the first axis works and I wonder how anything was ever machined pre DRO.
I bought 3 encoder strips 360 and 1 rotary encoder, the correct HEDS from USDigital. I looked around before parting with the cash and decided this was the cheapest route. There is much written on this list about glass and metal encoder strips with resolutions in the micron range and prices to match, but I am a machinist used to micrometers that read in thou and an old machine that has seen better days.
The HEDS are optical readers and you will not damage either them or the strip by just touching them together. If you look at the USDigital website they have drawings for the installation measurements.
The first decision is if the HED or the strip is going to be attached to the moving slide. I opted to move the HED alone the strip because it is easier to seal out the muck. Obtain a piece of aluminium angle of the required length that is straight, double sided tape and stick the encoder strip to it leaving the correct overhang for the HED. I screwed the angle to the machine and checked it with a dial gauge before sticking down the strip. Make up a block on which to mount the HED in the correct position, wire it up and check that the DRO works.
The next step is to seal out the grubby bits. I got a length of box section aluminium that the angle and the HED could fit inside leaving enough room for the wires. Then cut a slot along the length of the box to clear the angle and the run of the HED. I am using the same screws that mount the angle to mount the box. This means drilling corresponding holes in the front of the box so everything can be tightened up. These are then blocked up with little rubber bungs.
Feed the wires through and block up the ends and everything should be swarf and oil tight.
Terry.
Dear List,
Let me first say that I am in over my head and need advice. I am
trying to put together a DRO to measure travel of my Bridgeport knee.
The plan is to use a 2 axis DRO kit from Camtronics and a HEDS-9200
module with a 360 linear strip from US Digital. My questions concern
mounting of the linear strip. US Digital says this can be done using
double stick tape or drilling hole and using screws/aluminum mounts. Is
there a web site that might have a picture of a mounting? I know that
the protection of the encoder is also important. US Digital said that
linear strip runs inside module (makes sense) but doesn't touch it. If
it did touch would that destroy the strip or the module? Is it like
crashing a hard drive?
Any thoughts on this subject will be appreciated. I want to try this
installation rather than just buying a DRO.
Thanks in advance,
Richard Ronchi (Santa Clara, Ca)
[Non-text portions of this message have been removed]